212005921 has 8 divisors (see below), whose sum is σ = 221783400. Its totient is φ = 202392960.

The previous prime is 212005919. The next prime is 212005951. The reversal of 212005921 is 129500212.

It can be written as a sum of positive squares in 4 ways, for example, as 12321 + 211993600 = 111^2 + 14560^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212005921 - 2¹ = 212005919 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212005892 and 212005901.

It is not an unprimeable number, because it can be changed into a prime (212005951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38490 + ... + 43651.

It is an arithmetic number, because the mean of its divisors is an integer number (27722925).

Almost surely, 2^212005921 is an apocalyptic number.

It is an amenable number.

212005921 is a deficient number, since it is larger than the sum of its proper divisors (9777479).

212005921 is an equidigital number, since it uses as much as digits as its factorization.

212005921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82259.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 212005921 is about 14560.4231051161. The cubic root of 212005921 is about 596.2787468761.

The spelling of 212005921 in words is "two hundred twelve million, five thousand, nine hundred twenty-one".